DEGRADAÇÃO E BIORREMEDIAÇÃO DE COMPOSTOS DO PETRÓLEO POR BACTÉRIAS: REVISÃO

BACTERIAL DEGRADATION AND BIORREMEDIATION OF PETROLEUM COMPOUNDS: A REVIEW.  Petroleum is an organic compound formed by biogeochemical processes, consisting mostly of a complex mixture of hydrocarbons. Environmental contamination by this substance and its derivatives cause major ecological impact, and techniques for their remediation have been highlighted in recent decades. Polycyclic aromatic hydrocarbons (PAHs) from petrogenic origin are among the most persistent pollutants, with toxic, mutagenic and carcinogenic properties to humans. Most components of oil are biodegradable, however, it is a slow process and may take decades until complete environmental decontamination. Thus, bioremediation techniques have been the target of several studies in order to accelerate the decontamination process with less cost and less environmental damage. In this context, aerobic and anaerobic bacteria have shown great remediation potential of oil pollutants, being successfully used in various techniques, such as natural attenuation, bioaugmentation, bioestimualation, biosurfactants production, among others. This review describes some of these bioremediation techniques, as well as aerobic and anaerobic pathways for bacterial hydrocarbons metabolism and factors involved in its activity. Keywords: PAH; biosurfactant; aerobic metabolism; anaerobic metabolism; biodegradation.DEGRADACIÓN Y BIORREMEDIACIÓN DE COMPUESTOS DE PETRÓLEO POR BACTERIAS: UNA REVISIÓN. El petróleo es un compuesto orgánico formado por procesos biogeoquímicos, constituido principalmente por una mezcla compleja de hidrocarburos. La contaminación ambiental por esta sustancia y sus derivados causa un gran impacto ecológico y las técnicas para su remediación han sido destacadas en las últimas décadas. Los hidrocarburos aromáticos policíclicos (HAPs) de origen petrogénico, están entre los contaminantes de mayor persistencia, presentando propiedades tóxicas, mutagénicas y carcinogénicas en los seres humanos. La mayor parte de los componentes del petróleo es pasible de biodegradación. No obstante, este es un proceso lento, que puede tomar décadas hasta la total descontaminación del ambiente. Es así que las técnicas de biorremediación han sido objeto de de diversos estudios con el fin de acelerar el proceso de descontaminación con el menor costo y daño ambiental. En este contexto, las bacterias aeróbicas y anaeróbicas han mostrado un gran potencial para la biorremediación de contaminantes de petróleo, siendo usados con éxito en diversas técnicas, como la atenuación natural, bioaumentación, bioestimulación, producción de biosurfactantes, entre otros. Este trabajo describe algunas de estas técnicas, así como las vías aeróbicas y anaeróbicas para el metabolismo de hidrocarburos por bacterias y los factores que intervienen.Palabras clave: HAP; biosurfactante; metabolismo aeróbico; metabolismo anaeróbico; biodegradación.O petróleo é um composto orgânico, formado por processos biogeoquímicos, constituído em sua maior parte por uma mistura complexa de hidrocarbonetos. A contaminação ambiental por esta substância e por seus derivados causa grande impacto ecológico e as técnicas para sua remediação têm recebido destaque nas últimas décadas. Hidrocarbonetos aromáticos policíclicos (HAPs) de origem petrogênica estão entre os poluentes de maior persistência, apresentando propriedades tóxicas, mutagênicas e carcinogênicas aos seres humanos. A maior parte dos componentes do petróleo é passível de biodegradação, no entanto, trata-se de um processo lento, podendo levar décadas até a total descontaminação do ambiente. Assim, técnicas de biorremediação tem sido alvo de diversos estudos a fim de acelerar o processo de descontaminação com menor custo e menor dano ambiental. Neste contexto, bactérias aeróbicas e anaeróbicas têm demonstrado grande potencial para a remediação de poluentes do petróleo, sendo utilizadas com sucesso em diversas técnicas, como atenuação natural, bioaumentação, bioestimualação, produção de biossurfactantes, entre outras. Este trabalho descreve algumas destas técnicas, bem como as vias aeróbicas e anaeróbicas para o metabolismo de hidrocarbonetos por bactérias e seus fatores intervenientes

Galaxy and Mass Assembly (GAMA): halo formation times and halo assembly bias on the cosmic web

We present evidence for halo assembly bias as a function of geometric environment (GE). By classifying Galaxy and Mass Assembly (GAMA) galaxy groups as residing in voids, sheets, filaments or knots using a tidal tensor method, we find that low-mass haloes that reside in knots are older than haloes of the same mass that reside in voids. This result provides direct support to theories that link strong halo tidal interactions with halo assembly times. The trend with GE is reversed at large halo mass, with haloes in knots being younger than haloes of the same mass in voids. We find a clear signal of halo downsizing – more massive haloes host galaxies that assembled their stars earlier. This overall trend holds independently of GE. We support our analysis with an in-depth exploration of the L-Galaxies semi-analytic model, used here to correlate several galaxy properties with three different definitions of halo formation time. We find a complex relationship between halo formation time and galaxy properties, with significant scatter. We confirm that stellar mass to halo mass ratio, specific star formation rate (SFR) and mass-weighed age are reasonable proxies of halo formation time, especially at low halo masses. Instantaneous SFR is a poor indicator at all halo masses. Using the same semi-analytic model, we create mock spectral observations using complex star formation and chemical enrichment histories, which approximately mimic GAMA’s typical signal-to-noise ratio and wavelength range. We use these mocks to assert how well potential proxies of halo formation time may be recovered from GAMA-like spectroscopic data

Separating the anti-apoptotic and mitotic roles of survivin

Survivin is a bifunctional protein that acts as a suppressor of apoptosis and has an essential role in mitosis. To date whether these two functions can be divorced has not been addressed. Here we show that the linker region between the BIR (baculovirus inhibitor of apoptosis repeat) domain of survivin and COOH-terminal alpha helix may be the key to separating its roles. When overexpressed survivin is present in interphase cells and shuttles between the cytoplasm and nucleus. Here we identify a rev-like nuclear exportation signal (NES) in the central domain of survivin and demonstrate that point mutations within this region cause accumulation of survivin in the nucleus. Interestingly cells expressing NES mutants exhibit reduced survival after X-irradiation. Moreover, cells expressing survivin(L98A)-green fluorescent protein (GFP) showed increased poly(ADP-ribose) polymerase-cleavage and caspase-3 activity after tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment compared with cells expressing full-length survivin-green fluorescent protein. These data suggest a direct link between the interphase localization of survivin and cellular responsiveness to apoptotic stimuli. Using a cell proliferation assay, we also found that ectopic expression of NES mutants can complement for depletion of endogenous survivin, indicating that they can execute the mitotic duties of survivin. Thus we demonstrate for the first time that 1) survivin has a functional NES; 2) nuclear accumulation of overexpressed survivin correlates with increased sensitivity of cells to ionising radiation; and 3) the anti-apoptotic and mitotic roles of survivin can be separated through mutation of its NES. Separating these two functions of survivin could open up new possibilities for therapeutic strategies aimed at eliminating cancer cells yet preserving normal cell viability

SARS-CoV-2 omicron (B.1.1.529)-related COVID-19 sequelae in vaccinated and unvaccinated patients with cancer: results from the OnCovid registry

Background COVID-19 sequelae can affect about 15% of patients with cancer who survive the acute phase of SARS-CoV-2 infection and can substantially impair their survival and continuity of oncological care. We aimed to investigate whether previous immunisation affects long-term sequelae in the context of evolving variants of concern of SARS-CoV-2. Methods OnCovid is an active registry that includes patients aged 18 years or older from 37 institutions across Belgium, France, Germany, Italy, Spain, and the UK with a laboratory-confirmed diagnosis of COVID-19 and a history of solid or haematological malignancy, either active or in remission, followed up from COVID-19 diagnosis until death. We evaluated the prevalence of COVID-19 sequelae in patients who survived COVID-19 and underwent a formal clinical reassessment, categorising infection according to the date of diagnosis as the omicron (B.1.1.529) phase from Dec 15, 2021, to Jan 31, 2022; the alpha (B.1.1.7)-delta (B.1.617.2) phase from Dec 1, 2020, to Dec 14, 2021; and the pre-vaccination phase from Feb 27 to Nov 30, 2020. The prevalence of overall COVID-19 sequelae was compared according to SARS-CoV-2 immunisation status and in relation to post-COVID-19 survival and resumption of systemic anticancer therapy. This study is registered with ClinicalTrials.gov, NCT04393974. Findings At the follow-up update on June 20, 2022, 1909 eligible patients, evaluated after a median of 39 days (IQR 24-68) from COVID-19 diagnosis, were included (964 [ 50 center dot 7%] of 1902 patients with sex data were female and 938 [49 center dot 3%] were male). Overall, 317 (16 center dot 6%; 95% CI 14 center dot 8-18 center dot 5) of 1909 patients had at least one sequela from COVID-19 at the first oncological reassessment. The prevalence of COVID-19 sequelae was highest in the prevaccination phase (191 [19 center dot 1%; 95% CI 16 center dot 4-22 center dot 0] of 1000 patients). The prevalence was similar in the alpha-delta phase (110 [16 center dot 8%; 13 center dot 8- 20 center dot 3] of 653 patients, p=0 center dot 24), but significantly lower in the omicron phase (16 [6 center dot 2%; 3 center dot 5-10 center dot 2] of 256 patients, p<0 center dot 0001). In the alpha- delta phase, 84 (18 center dot 3%; 95% CI 14 center dot 6-22 center dot 7) of 458 unvaccinated patients and three (9 center dot 4%; 1 center dot 9- 27 center dot 3) of 32 unvaccinated patients in the omicron phase had sequelae. Patients who received a booster and those who received two vaccine doses had a significantly lower prevalence of overall COVID-19 sequelae than unvaccinated or partially vaccinated patients (ten [7 center dot 4%; 95% CI 3 center dot 5-13 center dot 5] of 136 boosted patients, 18 [9 center dot 8%; 5 center dot 8-15 center dot 5] of 183 patients who had two vaccine doses vs 277 [ 18 center dot 5%; 16 center dot 5-20 center dot 9] of 1489 unvaccinated patients, p=0 center dot 0001), respiratory sequelae (six [4 center dot 4%; 1 center dot 6-9 center dot 6], 11 [6 center dot 0%; 3 center dot 0-10 center dot 7] vs 148 [9 center dot 9%; 8 center dot 4- 11 center dot 6], p= 0 center dot 030), and prolonged fatigue (three [2 center dot 2%; 0 center dot 1-6 center dot 4], ten [5 center dot 4%; 2 center dot 6-10 center dot 0] vs 115 [7 center dot 7%; 6 center dot 3-9 center dot 3], p=0 center dot 037)

Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p &lt; 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

Some aspects of blistering and exfoliation of helium-hydrogen coimplanted (100) silicon

A Si(He,H) system, produced by ion implantation and suitable for SOI fabrication, is studied during and after the thermal treatment which induces surface blistering and exfoliation. The attention is focused on the influence of storage time between the implantation stage and the annealing stage, since it is expected that even at low temperatures the phenomena taking part in the blistering and exfoliation process are active. Three different storage environments are selected: (1) liquid nitrogen, (2) room temperature and (3) 100 \ub0C in air. The main result is that long time sample storage has the effect of decrease the exfoliation efficiency. Moreover, optimum conditions for exfoliation are met at storage time around 24 h at 100 \ub0C, where the maximum fraction (1) of the sample surface (about 16%) results exfoliated and (2) of He atoms (about 80%) are desorbed. The discussion evidences that He desorbtion during annealing and exfoliation efficiency are strictly correlated. Moreover, a phenomenological model explaining the observed storage effect is sketched, deduced from the present knowledge of the Si(H), Si(He) and Si(He,H) systems

A fast technique for the quantitative analysis of channeling RBS spectra

A straightforward method for the analysis of channeling RBS spectra is developed and validated. This method needs a minimum of computational complexity and does not require the a priori knowledge of the location of the scattering centres and of their dechanneling cross section. The method is applied to channeling RBS spectra obtained along the [100] direction in a hydrogen-implanted (100) silicon crystal to verify that the evaluated displaced-atom depth distribution is independent of the probe energy

Recrystallization of strainedlayers with various Gegradients and in the presence of impurities

The recrystallization of amorphous GexSi1-x thin films on Si with uniform and with increasing Ge content is studied. The amorphous-crystal interface roughness is modified by the presence of C and O impurities before entering the GexSi1-x layer. The crystallization kinetics are heavily affected by the resulting interface morphology. A minimum velocity is found in the region of the impurities where the interface starts to roughen; the strain effect induced by the Ge within the GexSi1-x is overcome and the crystallization proceeds according to kinetics very similar to those for pure Si

SEARCH FOR NUCLEAR-REACTIONS PRODUCED BY THE IMPACT OF HEAVY MOLECULAR-IONS ONTO LID

Preliminary evidence for light element fusions induced by the impact of heavy molecular ions, with mass around 430 a.m.u. (obtained by fragmentation of Re2(CO)10) and energy 140 keV, onto LiD target is presented. The experimental arrangement excludes the impact of fast light particles due to fragmentation inside the acceleration column and supports the idea of a > underlying physics